1. Field of the Invention
The present invention relates to an optical disk drive apparatus, and, in particular, to an optical disk drive apparatus wherein dirt and dust in the ambient environment effectively is prevented from entering the interior of the apparatus while the interior of the apparatus is effectively cooled thereby reducing the undesirable effects from dust and heat.
2. Description of the Prior Art
A conventional disk drive apparatus has a configuration similar to, for example, that illustrated in FIG. 2. This disk drive apparatus is provided with a casing or housing 8 and a main chassis 1, on which a spindle motor device 2 and a mechanism 4 for shifting the optical head 3 are mounted. These components are arranged together with an electrical equipment section 5, a power supply section 6, and a mechanism 7 for loading a disk D in a single space defined by the casing 8 and the main chassis 1.
An opening 10 for inserting and removing a disk cartridge and a shutter mechanism 11 are provided on the front face section of the casing 8, while a motor-driven fan 9 is provided on the rear face section of the casing 8 for cooling the inside of the casing 8. The space inside the casing 8 is cooled by a very small amount of air which passes through a gap in the shutter mechanism 11 for the disk insertion opening 10.
However, in such a conventional disk drive apparatus, the inside of the casing 8 is under a negative pressure, although small, resulting from the larger volume of air exhausted by the motor-driven fan 9 used for cooling than the amount of air flowing through the gap in the shutter mechanism 11. As a result, when the shutter mechanism 11 is opened in order that a disk cartridge is inserted or removed via the disk loading mechanism 7, there is a tendency for airborne contaminants such as dust and dirt in the ambient environment to enter the casing 8, which is a major problem. Specifically, when dust and dirt enter the apparatus, these impurities tend to adhere to an objective lens (omitted from the drawing) of the optical head, causing concern that reading and recording of signals will not be accurate.